Interlocking bucking hinge and ladder combination

ABSTRACT

A foldable ladder made up of at least four sections. Each section has a first side rail and a second side rail. The side rails of two of the sections are connected to the respective side rails of another section by an improved hinge. The hinge is made up of platelike bellcrank-shaped links stacked in parallel planes with spacers between the links. The spacers are the same thickness as the links. One leg of the links has its distal end interleaved between and pivoted to two distal ends of the links attached to the other section. When the ladder is unfolded, each link has an end that engages one of the ends of the spacer so that the sections of the ladder are held in rigid extended relation to each other. When the ladder is folded, two sections of the ladder define a space between them which receives two sections of the ladder. By using additional improved hinges, the ladder could be made with several sections.

Unite States Patent Goodwin INTERLOCKING BUCKING HINGE AND LADDERCOMBINATION [75] Inventor: Charles W. Goodwin, Erie, Pa.

[73] Assignee: PMCS Company, Inc., Erie, Pa.

[22] Filed: May 7, 1973 21 Appl. No; 357,926

[52] US. Cl. 182/163, 182/24 [51] Int. Cl. E06c U383 [58] Field ofSearch 182/24, 27, 23, 163, 164, 182/152; 16/157, 135

[5 6] References Cited UNITED STATES PATENTS 513,012 l/l894 Hall 182/27612,201 10/1898 Hart 16/157 1,587,383 6/l926 Kenneth 182/24 2,782,0752/1957 Fagan 182/152 3,231,045 l/l966 Lavrard 182/164 PrimaryExaminer-Reinaldo P. Machado [5 7 ABSTRACT A foldable ladder made up ofat least four sections. Each section has a first side rail and a secondside rail. The side rails of two of the sections are connected to therespective side rails of another section by an improved hinge. The hingeis made up of p1ate1ike bellcrank-shaped links stacked in parallelplanes with spacers between the links. The spacers are the samethickness as the links. One leg of the links has its distal endinterleaved between and pivoted to two distal ends of the links attachedto the other section. When the ladder is unfolded, each link has an endthat engages one of the ends of the spacer so that the sections of theladder are held in rigid extended relation to each other. When theladder is folded, two sections of the ladder define a space between themwhich receives two sections of the ladder. By using additional improvedhinges, the ladder could be made with several sections.

11 Claims, 9 Drawing Figures 43 1 14-$ O 3 1 L ir 3 9/1 13 HIE/4 L 21 20H H 2 ,/'12

27 2e LT,-

INTERLOCKING BUCKING HINGE AND LADDER COMBINATION REFERENCE TO PRIOR ARTThe hinge and ladder combination disclosed herein constitutes animprovement over the ladders shown in U.S. Pat. No. 3,081,840, U.S. Pat.No. 3,287,895, U.S. Pat. No. 3,239,862, U.S. Pat. No. 3,181,676 and U.S.Pat. No. 3,172,680. The ladders disclosed in the said patents are onlyable to fold one on top of the other. With the hinge disclosed herein,the ladder sections will fold with one end section between the other twosections.

OBJECTS OF THE INVENTION It is an object of the invention to provide animproved ladder.

Another object of the invention is to provide an improved combinationladder and hinge.

Another object of the invention is to provide an improved hinge.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawing and more particularlypointed out in the appended claims, it being understood that changes maybe made in the form, size, proportions, and minor details ofconstruction without departing from the spirit or sacrificing any of theadvantages of the invention.

GENERAL DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the ladderaccording to the invention.

FIG. 2 is an enlarged cross sectional view taken on line 22 of FIG. 1with the ladder folded.

FIG. 3 is a cross sectional view taken on line 33 of FIG. 1.

FIG. 4 is an enlarged partial front view of the hinge that joins thetopmost section to the intermediate section.

FIG. 5 is a diagram showing the ladder sections when folded.

FIG. 6 is an edge view of one of the links.

FIG. 7 is a side view of one of the links.

FIG. 8 is a side view of a spacer.

FIG. 9 is an end view of a spacer.

DETAILED DESCRIPTION OF THE DRAWINGS Now with more particular referenceto the drawings, the ladder 10 is of the general type of foldable laddershown in U.S. Pat. No. 3,081,840. For example, the ladder disclosed hasfour sections, a first intermediate section 11, a second intermediatesection 12, and a first outer section 13 and a second outer section 13',all hingedly connected together by hinges 18, 43 and 43.

The first intermediate section 11 has first side rail 14 and second siderail 15. Side rails 14 and are connected to the first side rail 22 andthe second side rail 23 of second intermediate section 12 by means ofhinges 42, and the first intermediate section 11 and first end sections13' are hingedly connected together by hinges 43. The first end section13 has a first side rail 24 and a second side rail and the second outersection 13 has first side rail 24 and second side rail 25.

Each side rail has a first end and a second end. The side rails of thefirst section 11 have first ends 16 and 17, and second ends 18 and 19respectively. The side rails of the second section have first ends 20and 21 and second ends. The side rails of the third section 13 havefirst ends 24 and 25 and second ends 26 and 27 respectively. The siderails of the several sections are connected together laterally by steps28.

The side rails of the ladder are preferably made of materialchannel-shaped in cross section. Each channel sectionhas a web 30 andflanges 31 and 32. The hinges 42 are made up of first L-shaped links 33and second .L-shaped links 34. The links 33 and 34 each have alongitudinal portion or leg 35 and lateral portion or leg 37, and asecond portion or leg 38. Legs 37 and 38 each fortn a projection andgudgeon. The links 33 and 34 each have a second lateral leg 37 whichextends laterally beyond the first legs 35 and 36 respectively. Thefirst links 33 are held in spaced relation to each other by spacers 46between them. The spacers 46 are rectangular and are shorter than thelinks 33 and 34 and an open space is provided between each two adjacentlinks. The ends of the first links 33 are interleaved between andreceive corresponding ends of the second links between them. The linksmay be fixed to the flanges of the channels by means of bolts 50. Thelegs 37 of links 33 are pivoted to the second leg 38 of links 34 by apivot 39 which may be a bolt that extends through all of the secondlinks of the particular hinge.

It will be noted that the ends 44 and 45 of the links 33 and 34respectively are flat and the ends 47 of spacers 46 terminate in spacedrelation to the ends 44 45 of the links 33 and 34. Thus when the ladderis in extended position for use, the ends '44 and 45 of the links extendbeyond the ends 47 of the spacers. A space is provided between thesections 11 and 1-2 and section 13 is received in this space when theladder is in folded position, as shown in FIG. 5.

It will be noted that the second ends 18 and 19 of the side rails 14 and15 are swingably connected to the first ends 20 and 21 of the side rails22 and 23 by hinges 42, shown in the enlarged view in FIG. 2.

It will likewise be noted that the second ends of the side rails 22 and23 of the section section 12 are swingably connected to the first ends24 and 25 of the side rails of second section 13 by means of hinges 43and fourth section 13 has its side rails connected to the side rails ofsection 11 by hinges 43'. Hinges ,43 and 43 may be of the type shownconnecting the several sections of legs of the ladder in U.S. Pat. No.3,081 ,840or they could be any other suitable type of hinge.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood is broadly novel as is commensurate with theappended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows: I

l. A hinge comprising a first stack of platelike members and a secondstack of platelike members,

said first stack of platelike members comprising first links havingfirst spacers disposed therebetween,

and said second stack of platelike members comprising second linkshaving second spacers disposed therebetween,

a first end of said first links extending beyond a first end of saidfirst spacers,

and a first end of said second links extending beyond the first end ofsaid second spacers,

said first links having laterally extending portions extending laterallybeyond the sides of said first spacers,

said second links having laterally extending portions extendinglaterally beyond said sides of said second spacers and disposed betweensaid laterally extending side portions of said first links,

pivot means connecting said side portions of said first links to thelaterally extending side portions of said second links,

the ends of said first portion of said second links being adapted toengage the ends of said first spacers when said second links are swunginto alignment with said first links,

said first links and said second links defining a space between whensaid second links are swung into spaced parallel relation to said firstlinks.

2. The hinge recited in claim 1 wherein a first channel member hasspaced flanges and a web is provided,

equal to the width of a said flange on said channel whereby a thirdchannel can be disposed between said first channel and said secondchannel when said channels are swung into spaced parallel relation witheach other.

3. The hinge recited in claim 1 wherein said links are L-shaped and havea first leg comprising said first portion and a second leg comprisingsaid second portion,

said first leg of said first link being disposed between the flanges ofsaid first channel,

and said first leg of said second link being disposed between theflanges of said second channel,

and said second leg of said first link extending beyond the said firstleg in l .-shaped relation,

the said second legs of said first links being disposed between the saidsecond flanges of said second channel,

and said pivot means extending through said second legs of said firstlinks and said second links.

4. The hinge recited in claim 3 wherein the first ends of said spacersterminate a distance from'the ends of said links equal to twice thedistance from said pivot to the edge of said links whereby the saidsecond link engages said first spacers to hold said links in alignmentwith each other.

5. A hinge and ladder combination comprising,

a foldable extension ladder having a plurality of substantially rigidrelatively adjoining ladder forming sections,

each of said sections including a pair of relatively spaced apartlongitudinally extending side rails and at least one step-forming memberextending transversely between said side rails and fixed thereto,

said sections comprising a first section, a second secsaid second end ofsaid second section being swingably connected to the first end of saidthird section by second hinges,

said first hinges each comprising a plurality of first links held inspaced relation to each other by means of first spacers,

and second links held together by means of second spacers,

each said link being platelike in construction and being ofsubstantially the same thickness as said spacers,

each said link having a first leg and a second leg integrally joinedtogether,

the first leg of said first links being fixed to the second end of saidfirst section of said ladder,

said first leg of said second links being fixed to said first end ofsaidsecond section side rails,

the distal ends of said second legs of said first links being pivotallyconnected to the distal ends of second legs of said second links,

' and pivot means connecting said distal ends together,

third section is adapted to swing between said first section and saidsecond section when said ladder sections lie in parallel planes.

7. The combination recited in claim 6 wherein said side rails are in theform of channels and said hinges are disposed between said channels.

8. A hinge comprising a group of first members and a group of secondmembers,

said first members being spaced from said second members,

said first members and said second members being adapted to be connectedto two spaced members to swingably connect said spaced members,

each said first member and said second member-hav-v ing a gudgeon on thedistal end thereof disposed in the space between said members,

and pivot means extending through said gudgeons swingably connectingsaid first members to said second members,

said groups of first members and second members comprise a first stackof platelike members and a second stack of platelike membersrespectively, said second stack of platelike members laterally spacedfrom said first stack,

each alternate plate in each said stack having a projection extendingtoward the other said stack,

a spacer between each two adjacent plates in each said stack formingstops for said first platelike members and said second platelikemembers,

each said projection in said first stack being disposed between twoadjacent plates in said second stack,

and a pin passing through said gudgeons on the distal ends of saidprojections.

9. The hinge recited in claim 8 wherein said platelike members are fixedto a first section and a second section of a ladder whereby said twosections are swingably connected together,

said first section and said second section each having an end sectionswingably connected thereto,

said end sections adapted to swing between the space between said firstsection and said second section when said ladder is folded,

and said pin extends through each said section.

10. A ladder comprising a first intermediate section and a secondintermediate section,

first hinge means swingably connecting said first intermediate sectionto said second intermediate section,

a first end section and a second end section,

second hinge means swingably connecting said first end section to saidfirst intermediate section,

and third hinge means swingably connecting said sec ond end section tosaid second intermediate section,

said end sections being adapted to swing into parallel relation withsaid first intermediate section and said second intermediate section,said intermediate sections being adapted to swing into spaced parallelrelation with each other providing a space to receive said first endsection and said second end section whereby said sections are disposedin parallel planes. said sections being further adapted to swing intoalignment with each other,

and stop means limiting the swinging of said sections relative to eachother when said sections are in alignment,

said first hinge member, said second hinge member,

and said third hinge member comprising said stop means for limiting theswinging movement of said sections relative to each other to hold saidsections in alignment during use,

said hinge means comprise a plurality of L-shaped links fixed to eachsaid intermediate section,

a plurality of spacers disposed between said L-shaped links providingstops,

pivot means connecting said L-shaped links together whereby said endsections are disposed between said intermediate sections when saidladder is folded.

11. The ladder recited in claim 10 wherein said links connected to oneintermediate section are co-planar with the spacers connected betweenthe links attached to said other intermediate section whereby said linksattached to one said intermediate section swing into engagement withsaid spacers between said other intermediate section when said ladder isextended.

l =l l l I

1. A hinge comprising a first stack of platelike members and a secondstack of platelike members, said first stack of platelike memberscomprising first links haVing first spacers disposed therebetween, andsaid second stack of platelike members comprising second links havingsecond spacers disposed therebetween, a first end of said first linksextending beyond a first end of said first spacers, and a first end ofsaid second links extending beyond the first end of said second spacers,said first links having laterally eXtending portions extending laterallybeyond the sides of said first spacers, said second links havinglaterally extending portions extending laterally beyond said sides ofsaid second spacers and disposed between said laterally extending sideportions of said first links, pivot means connecting said side portionsof said first links to the laterally extending side portions of saidsecond links, the ends of said first portion of said second links beingadapted to engage the ends of said first spacers when said second linksare swung into alignment with said first links, said first links andsaid second links defining a space between when said second links areswung into spaced parallel relation to said first links.
 2. The hingerecited in claim 1 wherein a first channel member has spaced flanges anda web is provided, a second channel member having spaced flanges and aweb is provided, said first portions of said first links are disposedbetween the flanges of said first channel and said first portions ofsaid second links are disposed between the flanges of said secondchannel, and said channels are swingable from positions in alignmentwith each other to a position in spaced parallel relation to each other,the space between said channels being approximately equal to the widthof a said flange on said channel whereby a third channel can be disposedbetween said first channel and said second channel when said channelsare swung into spaced parallel relation with each other.
 3. The hingerecited in claim 1 wherein said links are L-shaped and have a first legcomprising said first portion and a second leg comprising said secondportion, said first leg of said first link being disposed between theflanges of said first channel, and said first leg of said second linkbeing disposed between the flanges of said second channel, and saidsecond leg of said first link extending beyond the said first leg inL-shaped relation, the said second legs of said first links beingdisposed between the said second flanges of said second channel, andsaid pivot means extending through said second legs of said first linksand said second links.
 4. The hinge recited in claim 3 wherein the firstends of said spacers terminate a distance from the ends of said linksequal to twice the distance from said pivot to the edge of said linkswhereby the said second link engages said first spacers to hold saidlinks in alignment with each other.
 5. A hinge and ladder combinationcomprising, a foldable extension ladder having a plurality ofsubstantially rigid relatively adjoining ladder forming sections, eachof said sections including a pair of relatively spaced apartlongitudinally extending side rails and at least one step-forming memberextending transversely between said side rails and fixed thereto, saidsections comprising a first section, a second section and a thirdsection, each said section having a first side rail and a second siderail, the side rails of said ladder being made up of sections comprisingthe side rails of said first section, said second section, and saidthird section, said side rails of said first section, said secondsection and said third section each having a first end and a second end,the first end of the side rails of said first section being swingablyconnected to a second end of the side rails of said second section bymeans of first hinges, said second end of said second section beingswingably connected to the first end of said third section by secondhinges, said first hinges each comprising a plurality of first linksheld in spaced relation to each other by means of first spacers, andsecond links held together by means of second spacers, each said linkbeing platelike in construction and being of substantially the samethickness as said spacers, each said link having a first leg and asecond leg integrally joined together, thE first leg of said first linksbeing fixed to the second end of said first section of said ladder, saidfirst leg of said second links being fixed to said first end of saidsecond section side rails, the distal ends of said second legs of saidfirst links being pivotally connected to the distal ends of second legsof said second links, and pivot means connecting said distal endstogether, the ends of said spacers being disposed from the ends of saidfirst legs of said links an amount substantially equal to the distancesaid pivot means is from said edges whereby said first spacers engagesaid fist legs of said first links when said ladder is in unfoldedposition whereby the swinging of said first and said second sectionsrelative to each other is limited.
 6. The combination recited in claim 5wherein said third section is adapted to swing between said firstsection and said second section when said ladder sections lie inparallel planes.
 7. The combination recited in claim 6 wherein said siderails are in the form of channels and said hinges are disposed betweensaid channels.
 8. A hinge comprising a group of first members and agroup of second members, said first members being spaced from saidsecond members, said first members and said second members being adaptedto be connected to two spaced members to swingably connect said spacedmembers, each said first member and said second member having a gudgeonon the distal end thereof disposed in the space between said members,and pivot means extending through said gudgeons swingably connectingsaid first members to said second members, said groups of first membersand second members comprise a first stack of platelike members and asecond stack of platelike members respectively, said second stack ofplatelike members laterally spaced from said first stack, each alternateplate in each said stack having a projection extending toward the othersaid stack, a spacer between each two adjacent plates in each said stackforming stops for said first platelike members and said second platelikemembers, each said projection in said first stack being disposed betweentwo adjacent plates in said second stack, and a pin passing through saidgudgeons on the distal ends of said projections.
 9. The hinge recited inclaim 8 wherein said platelike members are fixed to a first section anda second section of a ladder whereby said two sections are swingablyconnected together, said first section and said second section eachhaving an end section swingably connected thereto, said end sectionsadapted to swing between the space between said first section and saidsecond section when said ladder is folded, and said pin extends througheach said section.
 10. A ladder comprising a first intermediate sectionand a second intermediate section, first hinge means swingablyconnecting said first intermediate section to said second intermediatesection, a first end section and a second end section, second hingemeans swingably connecting said first end section to said firstintermediate section, and third hinge means swingably connecting saidsecond end section to said second intermediate section, said endsections being adapted to swing into parallel relation with said firstintermediate section and said second intermediate section, saidintermediate sections being adapted to swing into spaced parallelrelation with each other providing a space to receive said first endsection and said second end section whereby said sections are disposedin parallel planes, said sections being further adapted to swing intoalignment with each other, and stop means limiting the swinging of saidsections relative to each other when said sections are in alignment,said first hinge member, said second hinge member, and said third hingemember comprising said stop means for limiting the swinging movement ofsaid sections relative to each other to hold said sections in alignmentduring use, said hinge means comprise a plurality of L-shaped linksfixed to each said intermediate section, a plurality of spacers disposedbetween said L-shaped links providing stops, pivot means connecting saidL-shaped links together whereby said end sections are disposed betweensaid intermediate sections when said ladder is folded.
 11. The ladderrecited in claim 10 wherein said links connected to one intermediatesection are co-planar with the spacers connected between the linksattached to said other intermediate section whereby said links attachedto one said intermediate section swing into engagement with said spacersbetween said other intermediate section when said ladder is extended.